RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. Pat. Appl. 08/711,422 filed 9/5/1996,
now U.S. Pat. 5,756,226, issued 5/26/1998.
FIELD OF INVENTION
[0002] The present invention is related to transparent media for ink printing. More specifically,
this invention is related to a transparent media and a process for forming the media.
The media has superior clarity, resistance to scratching and excellent adhesion to
phase change inks.
BACKGROUND OF THE INVENTION
[0003] Transparent films which display information are widely used throughout many different
industries and for many applications. Typically, a positive image is formed by placing
an ink or pigment onto a transparent plastic sheet. The image is then displayed by
projection or by light transmission.
[0004] Many methods are available for printing a positive image onto a transparent plastic
sheet. Ink jet printers, and their associated ink formulations, are well advanced
technically; and aqueous ink jet printers represent a respectable share of the total
printing market. Aqueous ink jet printing is particularly advantageous for printing
text or images where the printed area covers a small portion of the area of the transparent
sheet. However, aqueous ink jet printing is less suitable for printing large areas
of a transparent plastic sheet since a large volume of solvent must be removed from
the media. The volume of solvent increases with image density which leads a skilled
artisan away from ink jet printing for high optical density, large print area applications.
[0005] Phase change ink printing corrects many of the deficiencies of aqueous ink jet printing.
A high optical density can be obtained and large areas can be printed without evaporation
of solvent. The impact of phase change ink printing in the market place has been impeded
due to the lack of a suitable transparent media. Media designed for use with aqueous
or other solvent based ink jet printers is unsuitable due to the large coating weight
of the ink receptive layer which is required to absorb the ink solvent. Furthermore,
the-coatings used for aqueous or solvent ink jet media do not provide adequate adhesion
for the phase change ink composition. Thus, there is a need for a media which will
take full advantage of the properties offered by phase change ink printing.
[0006] Compositions described in commonly assigned U.S. Pat. 5,756,226 demonstrate adequate
performance when used with phase change ink jet printing methods. Improvements in
ink adhesion are still desired to insure adequate adhesion between the ink and the
media. An overcoat comprising a softer polymer mixture is demonstrated herein to provide
superior adhesion.
[0007] Japanese unexamined Patent Appl. Kokai 6-32046 teaches the addition of up to 10%,
by weight, of a zirconium compound to improve the print quality. Japanese unexamined
Patent Application Kokai 4-364,947 utilizes TiO
2 in a similar manner. The transparency of the coated layer is compromised by the addition
of zirconium or titanium solids rendering the film unsuitable for use as a transparent
media. Japanese unexamined Patent Appl. Kokai 4-201,286 teaches media which is suitable
for aqueous ink jet printing yet the surface is susceptible to scratching. High scratch
susceptibility renders a media unacceptable for use in automatic printing devices
and for high quality printing applications.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide an improved media for use with
phase change ink printing.
[0009] It is a particular object of the present invention to provide a media which has improved
resistance to surface scratching and improved adhesion with phase change inks.
[0010] A particular advantage offered by the present invention is the clarity which can
be obtained and the suitability for use as a transparency media. The present invention
is superior for printing applications requiring high clarity in unprinted areas.
[0011] These and other advantages, as will be apparent from the teachings herein, is demonstrated
in a phase change ink recording media comprising: a polyethylene terephthalate support;
a 1-15 mg/dm
2 lower receptor layer coated on the support wherein the lower receptor layer comprises:
silica; and at least one polymer chosen from a set consisting of polyvinyl alcohol,
polyvinyl pyrrolidone, polyacrylamide, methylcellulose and gelatin; wherein a total
weight of the polymer and the silica is 82-97%, by weight, silica and 3-18%, by weight,
polymer; and an upper receptive layer coated on said lower receptor layer wherein
said upper receptor layer comprises: 32-70%, by weight, matrix polymer; 15-62%, by
weight, inorganic particulate material; and 5-53%, by weight, soft polymer mixture.
[0012] The advantages offered by the present invention are particularly well suited for
use with phase change inks. The superiority of the media is demonstrated in a process
for forming a printed image comprising the steps of:
i) heating a solid phase change ink to form a liquid phase change ink;
ii) applying the liquid phase change ink to a transfer surface in a pattern;
iii) cooling the liquid phase change ink on the transfer surface to form an image
of the pattern;
iv) transferring the solid image to a receptor comprising:
a 1-10 mil thick polyethylene terephthalate support; and
a 1-15 mg/dm2 lower receptor layer coated on the support
wherein the lower receptor layer comprises:
a fibrous, branched, silica with a particle size of no more than 0.3 µm; and
a polymer chosen from a set consisting of polyvinyl alcohol, polyacrylamide and gelatin;and
v) fixing the solid image to the receptor.
[0013] A preferred method for forming a transparent recording material for phase change
ink recording comprising the steps of: making an aqueous coating solution comprising:
water; a binder composition comprising: at least one polymer chosen from a group consisting
of polyvinyl alcohol, polyacrylamide, methyl cellulose, polyvinyl pyrrolidone and
gelatin; and an inorganic particulate material with an average particle size of no
more than 0.3 µm wherein the inorganic particulate material represents at least 82%,
by weight, and no more than 97%, by weight, of a combined coating weight of the polymer
and the inorganic particulate material taken together; wherein the aqueous coating
solution has an ionic conductivity of no more than 0.6 mS at 25°C; applying the coating
solution to a polyethyleneterephthalate support in a sufficient amount that the inorganic
particulate material and said polymer taken together weigh 1 - 15 mg/dm
2; removing the water from the coating solution.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The inventive media comprises a support with a receptive layer coated thereon. The
receptive layer preferably comprises a lower receptive layer coated on the support
and an upper receptive layer coated on the lower receptive layer. Throughout the specification
"lower receptive layer" refers to the layer closest to the support and "upper receptive
layer" refers to the layer furthest from the support. "Receptive layer" refers to
the layer which includes a lower receptive layer and optionally an upper receptive
layer.
[0015] The lower receptive layer comprises a binder and an inorganic particulate material.
The binder comprises at least one water soluble polymer. The prefered water soluble
polymers are chosen based on low ionic content and the presence of groups capable
of adhering to silica. The water soluble polymer is most preferably chosen from polyvinyl
alcohol, acrylates, hydrolyzed polyacrylamide, methyl cellulose, polyvinyl pyrrolidone,
gelatin and copolymers thereof. Copolymers and grafted polymers are suitable provided
they are water soluble or water dispersable and dry to a clear coat. Particularly
suitable copolymers comprise acrylic acid/vinyl pyrrolidone copolymers and urethane/acrylate
copolymers. More preferably, the binder comprises at least one polymer chosen from
a group consisting of polyvinyl alcohol, polyvinyl pyrrolidone and gelatin. Most preferably,
the binder comprises polymerized monomer chosen from vinyl alcohol, acrylamide, vinyl
pyrrolidone and combinations thereof.
[0016] Throughout the specification, percentages of lower receptive layer components will
be presented based on the combined weight of the polymers and the inorganic particulate
material only, unless otherwise stated.
[0017] The inorganic particulate material of the lower receptor layer represents at least
82%, by weight, and no more than 97%, by weight, of the total weight of the polymer
and inorganic particulate material taken together. Above 97%, by weight, inorganic
particulate material the scratch resistance of the film deteriorates to levels which
are unacceptable for use in high quality printing. Below 82%, by weight, inorganic
particulate material the adhesion between phase change inks and the surface of the
substrate, as measured by the tape test, decreases to levels which are unacceptable.
Preferably the inorganic particulate material represents at least 89% and no more
than 95% of the total weight of the polymer and inorganic particulate material taken
together. Most preferably the inorganic particulate material represents 90-95% of
the total weight of the polymer and inorganic particulate material taken together.
[0018] Average particle size is determined as the hydrodynamic particle size in water and
is the size of a spherical particle with the sane hydrodynamic properties as the sample
in question. By way of example, a fibrous silica particle with actual dimensions on
the order of 0.150 µm by 0.014 µm has a hydrodynamic particle size of approximately
0.035 µm.
[0019] The degree of ionization of silica plays an important role in the degree of ionization
of the coating solution. The degree of ionization of the coating solution has been
determined to play a major role in the clarity of the final media. The degree of ionization
can be measured as the ionic strength of the coating formulation which is determined
from the ionic conductivity of the coating solution prior to application on the support.
Preferred is a total coating solution ionic conductivity of no more than 0.6 mS (Siemens
x 10
3) as measured at 25°C at 10%, by weight, total solids, on a properly standardized
EC Meter Model 19101-00 available from Cole-Parmer Instrument Company of Chicago Ill.,
USA. More preferred is an ionic conductivity of no more than 0.5 mS, when measured
at 25°C at 10%, by weight, total solids. Most preferred is an ionic conductivity of
no more than 0.3 mS, when measured at 25°C at 10%, by weight, total solids.
[0020] The coating weight of the inorganic particulate material and the polymer is preferably
at least 1 mg/dm
2 and no more than 15 mg/dm
2 per side for the lower receptive layer. Above 15 mg/dm
2 the scratch resistance decreases to unacceptable levels for high quality printing.
Below 1 mg/dm
2 phase change inks adhesion to the coating decreases to unacceptable levels and the
the coating quality diminishes requiring either decreased production rates or increases
in the amount of unusable material both of which increase the cost of manufacture
for the media. More preferably, the coating weight of the inorganic particulate material
and the polymer is no more than 8 mg/dm
2 and most preferably the coating weight is no more than 5 mg/dm
2.
[0021] The upper receptive layer is coated supra the lower receptive layer. Intervening
layers may he employed if desired for convenience, however, their use is not required
to realize the advantage of the present invention.
[0022] The dried coating weight of the upper receptive layer is preferably 1-6 mg/dm
2. More preferably the dried coating weight of the upper receptive layer is 3-5
-mg/dm
2. Most preferably the dried coating weight of the upper receptive layer is approximately
4 mg/dm
2.
[0023] The coating composition for the upper receptive layer comprises a matrix polymer,
an inorganic particulate material and a soft polymer mixture.
[0024] The upper receptive layer preferably comprises 32-70%, by weight, matrix polymer;
15-62%, by weight, inorganic particulate material and 5-15%, by weight, soft polymer
mixture. More preferably, the upper receptive layer preferably comprises 40-70%, by
weight, matrix polymer and more preferably 60-65%, by weight matrix polymer. Preferably,
the upper receptive layer comprises 15-35%, by weight, inorganic particulate material
and more preferably 20-30%, by weight, inorganic particulate material. Preferably,
the upper receptive layer comprises 10-15%, by weight, soft polymer mixture.
[0025] The preferred matrix polymer is chosen from polyvinyl alcohol, acrylates, hydrolyzed
polyacrylamide, methyl cellulose, polyvinyl pyrrolidone, gelatin and copolymers thereof.
Copolymers and grafted polymers are suitable provided they are water soluble or water
dispersable and dry to a clear coat. Particularly suitable copolymers comprise acrylic
acid/vinyl pyrrolidone copolymers and urethane/acrylate copolymers. More preferably,
the matrix polymer comprises at least one polymer chosen from a group consisting of
polyvinyl alcohol, polyvinyl pyrrolidone and gelatin. Most preferably, the matrix
polymer comprises polymerized monomer chosen from vinyl alcohol, acrylamide, vinyl
pyrrolidone and combinations thereof. Polyvinyl alcohol is the most preferred matrix
polymer.
[0026] The soft polymer mixture improves adhesion between the phase change ink and the upper
receptive layer.
[0027] The term "soft polymer mixture" describes a polymer, or mixture of polymers that
soften during the image transfer step of phase change ink printing. The softening
allows the phase change ink and receptive layer to become chemically or physically
mated for superior durability. The soft polymer matrix must be sufficiently soft to
allow the ink and coating to become intimately interrellated and yet rigid enough
to avoid scratching and sticking with adjoining films.
[0028] The prefered soft polymer mixture comprises methyl acrylate, acrylic acid and sodium
acrylate. Preferably, the soft polymer mixture comprises methyl acrylate representng
2-24%, by weight, of the upper receptive layer; acrylic acid representing 1-10%, by
weight, of the upper receptive layer; and sodium acrylate representing 1-19%, by weight,
of the upper receptive layer. More preferably, the soft polymer mixture comprises
methyl acrylate representing 5-6%, by weight, of the upper receptive layer; acrylic
acid representing 3-4%, by weight, of the upper receptive layer and sodium acrylate
representing 4-5%, by weight, of the upper receptive layer.
[0029] It is optional, but preferable, to incorporate large particles in the upper receptive
layer to increase surface area. Large particles are defined as nonreactive particles
over 6 µm in size with preferred large particles being no more than 10 µm in size.
The most preferred large particle are chosen from polymethylmethacrylate beads, styrene
beads, glass beads, teflon beads, and the like. It is preferable that the large particles
be added in an amount sufficient to provide approximately 10-80 particles per 5000
µm
2 of coated material. More preferably the large particles are added in an amount sufficient
to provide 40-60 particles per 5000 µm
2 of coated material.
[0030] The inorganic particulate material is preferably chosen from a set consisting of
colloidal silica and alumina. The preferred inorganic particulate material is colloidal
silica with an average particle size of no more than 0.3µm. More preferably the inorganic
particulate material is colloidal silica with an average particle size of no more
than 0.1µm. Most preferably the inorganic particulate material is colloidal silica
with an average particle size of no more than about 0.03µm. The average particle size
of the colloidal silica is preferably at least 0.005 µm. A particularly preferred
colloidal silica is a multispherically coupled and/or branched form, also referred
to as fibrous, branched silica. Specific examples include colloidal silica particles
having a long chain structure in which spherical colloidal silica is coupled in a
multispherical form, and the colloidal silica in which the coupled silica is branched.
The coupled colloidal silica is obtained by forming particle-particle bonds between
primary particles of spherical silica. The particle-particle bonds are formed with
metallic ions having a valence of two or more interspersed between the primary particles
of spherical silica. Preferred is a colloidal silica in which at least three particles
are coupled together. More preferably at least five particles are coupled together
and most preferably at least seven particles are coupled together.
[0031] It is preferable to add a cross linker to the receptive layer to increase the strength
of the tied coating. Preferred cross linkers are siloxane or silica silanols. Particularly
suitable hardeners are defined by the formula, R
1nSi(OR
2)
4-n where R
1 is an alkyl, or substituted alkyl, of 1 to 18 carbons; R
2 is hydrogen, or an alkyl, or substituted alkyl, of 1 to 18 carbons; and n is an integer
of 1 or 2. Aldehyde hardeners such as formaldehyde or glutaraldehyde are suitable
hardeners. Pyridinium based hardeners such as those described in, for example, U.S.
Pat. Nos. 3,880,665, 4,418,142, 4,063,952 and 4,014,86; imidazolium hardeners as defined
U.S. Pat No. 5,459,029; U.S. Pat No. 5,378,842; US Pat. Appl. 08/463,793 filed 6/5/95
(IM-0963B), and US Pat. Appl. 08/401,057 filed 3/8/95 (IM-0937) are suitable for use
in the present invention. Aziridenes and epoxides are also effective hardeners.
[0032] Crosslinking is well known in the art to form intermolecular bonds between various
molecules and surfaces thereby forming a network. In the instant invention a crosslinker
may be chosen to form intermolecular bonds between pairs of water soluble polymers,
between pairs of water insoluble polymers, or between water soluble polymers and water
insoluble polymers. If crosslinking is applied it is most preferable to crosslink
the polymers to the inorganic particulate matter. It is preferable to apply any crosslinking
additive just prior to or during coating. It is contemplated that the crosslinking
may occur prior to formation of the coating solution or in situ.
[0033] The term "gelatin" as used herein refers to the protein substances which are derived
from collagen. In the context of the present invention "gelatin" also refers to substantially
equivalent substances such as synthetic derivatives of gelatin. Generally gelatin
is classified as alkaline gelatin, acidic gelatin or enzymatic gelatin. Alkaline gelatin
is obtained from the treatment of collagen with a base such as calcium hydroxide,
for example. Acidic gelatin is that which is obtained from the treatment of collagen
in acid such as, for example, hydrochloric acid. Enzymatic gelatin is generated by
a hydrolase treatment of collagen. The teachings of the present invention are not
restricted to gelatin type or the molecular weight of the gelatin. Carboxyl-containing
and amine containing polymers, or copolymers, can be modified to lessen water absorption
without degrading the desirable properties associated with such polymers and copolymers.
[0034] Other materials can be added to the receptive layer to aid in coating and to alter
the rheological properties of either the coating solution or the dried layer. Polymethylmethacrylate
beads can be added to assist with transport through phase change ink printers. Care
must be taken to insure that the amount of beads is maintained at a low enough level
to insure that adhesion of the phase change ink to the substrate and the high clarity
is not deteriorated. It is conventional to add surfactants to a coating solution to
improve the coating quality. Surfactants and conventional coating aids are compatible
with the present invention.
[0035] The preferred support is a polyester obtained from the condensation polymerization
of a diol and a dicarboxylic acid. Preferred dicarboxylic acids include terephthalate
acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, adipic acid and
sebacic acid. Preferred diols include ethylene glycol, trimethylene glycol, tetramethylene
glycol and cyclohexanedimethanol. Specific polyesters suitable for use in the present
invention are polyethylene terephthalate, polyethylene-p-hydroxybenzoate, poly-1,4-cyclohexylene
dimethylene terephthalate, and polyethylene-2,6-naphthalenecarboyxlate. Polyethylene
terephthalate is the most preferred polyester for the support due to superior water
resistance, chemical resistance and durability. The polyester support is preferably
1-10 mil in thickness. More preferably the polyester support is 3-8 mil thick and
most preferably the polyester support is either 3.5-4.5 mil or 6-8 mil thick.
[0036] A primer layer is preferably included between the ink receptor layer and the support
to improve adhesion therebetween. Preferred primer layers are resin layers or antistatic
layers. Resin and antistatic primer layers ate described in U.S. Pats. 3,567,452;
4,916,011; 4,701,403; 4,891,308; 4,225,665, 5,554,447.
[0037] The primer layer is typically applied, and dry-cured during the manufacture of the
polyester support. Then polyethylene terephthalate is manufactured for use as a photographic
support, the polymer is cast as a film, the mixed polymer primer layer composition
is applied to one or both sides and the structure which is then biaxially stretched.
The biaxial stretching is optionally followed by coating of a gelatin subbing layer.
Upon completion of stretching and the application of the subbing layer compositions,
it is necessary to remove strain and tension in the support by a heat treatment comparable
to the annealing of glass. Air temperatures of from 100°C to 160°C are typically used
for this heat treatment.
[0038] It is prefered to activate the surface of the support prior to coating to improve
the coating quality thereon. The activation can be accomplished by corona-discharge,
glow-discharge, UV-rays or flame treatment. Corona-discharge is preferred and can
be carried out to apply an energy of 1 mw to 1 kw/m
2. More preferred is an energy of 0.1 w to 5 w/m
2.
[0039] Bactericides may be added to any of the described layers to prevent bacteria growth.
Preferred are Kathon®, neomycin sulfate, and others as known in the art.
[0040] An optional, but preferred backing layer can be added to decrease curl, impart color,
assist in transport, and other properties as common to the art. Aforementioned antistatic
layers are suitable as backing layers. The backing layer may comprise cross linkers
to assist in the formation of a stronger matrix. Preferred cross linkers are carboxyl
activating agents as defined in Weatherill, USP 5,391,477. Most preferred are imidazolium
hardeners as defined in Fodor, et al, USP 5,459,029; USP 5,378,842; USP 5,591,863;
USP 5,601,971. The backing layer may also comprise transport beads such as polymethylmethacrylate.
It is known in the art to add various surfactants to improve coating quality. Such
teachings are relevant to the backing layer of the present invention.
[0041] Phase change inks are characterized, in part, by their propensity to remain in the
solid phase at ambient temperature and in the liquid phase at elevated temperatures
in the printing head. The ink is heated to form the liquid phase and droplets of liquid
ink are ejected from the printing head onto an optional transfer surface. The transfer
surface is maintained at a temperature which is suitable for maintaining the phase
change ink in a rubbery state. The ink droplets are then transferred to the surface
of the printing media maintained at 20-35°C wherein the phase change ink solidifies
to form a pattern of solid ink drops.
[0042] Exemplary phase change ink compositions comprise the combination of a phase change
ink carrier and a compatible colorant.
[0043] Exemplary phase change ink colorants comprise a phase change ink soluble complex
of (a) a tertiary alkyl primary amine and (b) dye chromophores having at least one
pendant acid functional group in the free acid form. Each of the dye chromophores
employed in producing the phase change ink colorants are characterized as follows:
(1) the unmodified counterpart dye chromophores employed in the formation of the chemical
modified dye chromophores have limited solubility in the phase change ink carrier
compositions, (2) the chemically modified dye chromophores have at least one free
acid group, and (3) the chemically modified dye chromophores form phase change ink
soluble complexes with tertiary alkyl primary amines. For example, the modified phase
change ink colorants can be produced from unmodified dye chromophores such as the
class of Color Index dyes referred to as Acid and Direct dyes. These unmodified dye
chromophores have limited solubility in the phase change ink carrier so that insufficient
color is produced from inks made from these carriers. The modified dye chromophore
preferably comprises a free acid derivative of a xanthene dye.
[0044] The tertiary alkyl primary amine typically includes alkyl groups having a total of
12 to 22 carbon atoms, and preferably from 12 to 14 carbon atoms. The tertiary alkyl
primary amines of particular interest are produced by Robin and Haas Texas, Incorporated
of Houston, Texas under the tradenames Primene JMT and Primene 81-R. Primene 81-R
is a particularly suitable material. The tertiary alkyl primary amine of this invention
comprises a composition represented by the structural formula:
wherein:
x is an integer of from 0 to 18;
y is an integer of from 0 to 18; and
z is an integer of from 0 to 18;
with the proviso that the integers x, y and z are chosen according to the relationship:
[0045] An exemplary phase change ink carrier comprises a fatty amide containing material.
The fatty amide-containing material of the phase change ink carrier composition may
comprise a tetraamide compound. Particularly suitable tetra-amide compounds for producing
phase change ink carrier compositions are dimeric acid-based tetra-amides including
the reaction product of a fatty acid, a diamine such as ethylene diamine and a dimer
acid. Fatty acids having from 10 to 22 carbon atoms are suitable in the formation
of the dimer acid-based tetra-amide. These dimer acid-based tetramides are produced
by Union Camp and comprise the reaction product of ethylene diamine, dimer acid, and
a fatty acid chosen from decanoic acid, myristic acid, stearic acid and docosanic
acid. Dimer acid-based tetraamide is the reaction product of diner acid, ethylene
diamine and stearic acid in a stoichiometric ratio of 1:2:2, respectively. Stearic
acid is a particularly suitable fatty acid reactant because its adduct with dimer
acid and ethylene diamine has the lowest viscosity of the dimer acid-based tetra-amides.
[0046] The fatty amide-containing material can also comprise a mono-amide. The phase change
ink carrier composition may comprise both a tetra-amide compound and a mono-amide
compound. The mono-amide compound typically comprises either a primary or secondary
mono-amide. Of the primary mono-amides stearamide, such as Kemamide S, manufactured
by Witco Chemical Company, can be employed herein. The mono-amides behenyl behemamide
and stearyl stearamide are extremely useful secondary mono-amides. Stearyl stearamide
is the mono-amide of choice in producing a phase change ink carrier composition.
[0047] Another way of describing the secondary mono-amide compound is by structural formula.
More specifically, the secondary mono-amide compound is represented by the structural
formula:
C
xH
y-CO-NHC
aH
b
wherein:
x is an integer from 5 to 21;
y is an integer from 11 to 43;
a is an integer from 6 to 22; and
b is an integer from 13 to 45.
[0048] The fatty amide-containing compounds comprise a plurality of fatty amide materials
which are physically compatible with each other. Typically, even when a plurality
of fatty amide-containing compounds are employed to produce the phase change ink carrier
composition, the carrier composition has a substantially single melting point transition.
The melting point of the phase change ink carrier composition is most suitably at
least about 70°C.
[0049] The phase change ink carrier composition may comprise a tetra-amide and a mono-amide.
The weight ratio of the tetra-amide to the mono-amide is from about 2:1 to 1:10.
[0050] Modifiers such as tackifiers and plasticizers may be added to the carrier composition
to increase the flexibility and adhesion. The tackifiers of choice are compatible
with fatty amide-containing materials. These include, for example, Foral 85, a glycerol
ester of hydrogenated abietic acid, and Foral 105, a pentaerythritol ester of hydroabietic
acid, both manufactured by Hercules Chemical Company; Nevtac 100 and Nevtac 80 which
are synthetic polyterpene resins manufactured by Neville Chemical Company; Wingtack
86, a modified synthetic polyterpene resin manufactured by Goodyear Chemical Company,
and Arakawa KE 311, a rosin ester manufactured by Arakawa Chemical Company. Arakawa
KE 311, is a particularly suitable tackifier for use phase change ink carrier compositions.
[0051] Plasticizers may be added to the phase change ink carrier to increase flexibility
and lower melt viscosity. Plasticizers which have been found to be advantageous in
the composition include dioctyl phthalate, diundecyl phthalate, alkylbenzyl phthalate
(Santicizer 278) and triphenyl phosphate, all manufactured by Monsanto Chemical Company;
tributoxyethyl phosphate (KP-140) manufactured by FMC Corporation; dicyclohexyl phthalate
(Morflex 150) manufactured by Morflex Chemical Company Inc.; and trioctyl trimellitate,
manufactured by Kodak. However, Santicizer 278 is a plasticizer of choice in producing
the phase change ink carrier composition.
[0052] Other materials may be added to the phase change ink carrier composition. In a typical
phase change ink carrier composition antioxidants are added for preventing discoloration.
Antioxidants include Irganox 1010, manufactured by Ciba Geigy, Naugard 76, Naugard
512, and Naugard 524, all manufactured by Uniroyal Chemical Company.
[0053] A particularly suitable phase change ink carrier composition comprises a tetra-amide
and a mono-amide compound, a tackifier, a plasticizer, and a viscosity modifying agent.
The compositional ranges of this phase change ink carrier composition are typically
as follows: from about 10 to 50 weight percent of a tetraamide compound, from about
30 to 80 weight percent of a mono-amide compound, from about 0 to 25 weight percent
of a tackifier, from about 0 to 25 weight percent of a plasticizer, and from about
0 to 10 weight percent of a viscosity modifying agent.
[0054] A phase change ink printed substrate is typically produced in a drop-on-demand ink
jet printer. The phase change ink is applied to at least one surface of the substrate
in the form of a predetermined pattern of solidified drops. The application of phase
change ink preferably involves a transfer. Upon contacting the substrate surface,
the phase change ink solidifies and adheres to the substrate. Each drop on the substrate
surface is non-uniform in thickness and transmits light in a non-rectilinear path.
[0055] The pattern of solidified phase change ink drops can, however, be reoriented to produce
a light-transmissive phase change ink film on the substrate which has a high degree
of lightness and chroma, when measured with a transmission spectrophotometer, and
which transmits light in a substantially rectilinear path. The reorientation step
involves the controlled formation of a phase change ink layer of a substantially uniform
thickness. After reorientation, the layer of light-transmissive ink will transmit
light in a substantially rectilinear path.
[0056] The transmission spectra for each of the phase change inks can be evaluated on a
commercially available spectrophotometer, the ACS Spectro-Sensor II, in accordance
with the measuring methods stipulated in ASTM E805 (Standard Practice of Instrumental
Methods of Color or Color Difference Measurements of Materials) using the appropriate
calibration standards supplied by the instrument manufacturer. For purposes of verifying
and quantifying the overall colorimetric performance, measurement data are reduced,
via tristimulus integration, following ASTM E308 (Standard Method for Computing the
Colors of Objects using the CIE System) in order to calculate the 1976 CIE L* (Lightness),
a* (redness-greeness), and b* (yellownessblueness); (CIELAB) values for each phase
change ink sample. In addition, the values for CIELAB Psychometric Chroma, C* sub
ab, and CIELAB Psychometric Hue Angle, h sub ab were calculated according to publication
CIE 15.2, Colorimetry (Second Edition, Central Bureau de la CIE, Vienna, 1986).
[0057] The nature of the phase change ink carrier composition is chosen such that thin films
of substantially uniform thickness exhibit a relatively high L* value. For example,
a substantially uniform thin film of about 20 - 70 µm thickness of the phase change
ink carrier preferably has an L* value of at least about 65.
[0058] The phase change ink carrier composition forms an ink by combining the same with
a colorant. A subtractive primary colored phase change ink set will be formed by combining
the ink carrier composition with compatible subtractive primary colorants. The subtractive
primary colored phase change inks comprise four component dyes, namely, cyan, magenta,
yellow and black. The subtractive primary colorants comprise dyes from either class
of Color Index (C.I.) Solvent Dyes and Disperse Dyes. Employment of some C.I. Basic
Dyes can also be successful by generating, in essence, an in situ Solvent Dye by the
addition of an equimolar amount of sodium stearate with the Basic Dye to the phase
change ink carrier composition. Acid Dyes and Direct Dyes are also compatible to a
certain extent.
[0059] The phase change inks formed therefrom have, in addition to a relatively high L*
value, a relatively high C*ab value when measured as a thin layer of substantially
uniform thickness as applied to a substrate. A reoriented layer of the phase change
ink composition on a substrate has a C*ab value, as a substantially uniform thin film
of about 20 µm thickness, of subtractive primary yellow, magenta and cyan phase change
ink compositions, which are at least about 40 for yellow ink compositions, at least
about 65 for magenta ink compositions, and at least about 30 for cyan ink compositions.
[0060] Tape test density is a quantitative measurement indicating, the propensity of the
phase change ink to remain adhered to the media. The tape test is performed by adhering,
using a 10 lb. roller weight, at least 10 cm of 3M Scotch Type 810 Magic Tape (19
mm wide) to cover all of a strip of a 5 cm x 5 cm square, maximum black density (Tektronix
016-1307-00 black wax) single layer wax ink crosshatched pattern (with 5 mm spaced
0.2 mm lines without ink) printed on the media using a Tektronix Phaser 340 in the
paper mode at 300 x 600 dpi, (monochrome) leaving approximately 1 cm of tape unattached.
By grasping the unattached tape tag, the tape is pulled off of the media and printed
area in one single rapid motion. The density of the peeled (Tp) and the original inked
(To) areas on the media are measured using a Macbeth TR927 densitometer zeroed with
the clear filter and using the "density" selection taking care to center the Macbeth
spot in a single 5 mm x 5 mm crosshatched square. A higher tape test density is preferred
since this indicates a smaller percentage of phase change ink removal. No removal
of phase change ink would be indicated by a tape test density of 100. Complete removal
of the phase change ink would be indicated by a tape test density of 0. Tape test
values are typically reproducible to a standard deviation of no larger than 5%. The
tape test density is the loss of transmittance according to the following formula:
where TT is relative tape test density retained;
Tp is % transmittance of the area after the tape is peeled off; and To is % transmittance
of the original inked area.
[0061] The relative tape test density retained following the tape test decreases with the
age of both the media and the printed area. The decrease is typically 10% of the initial
value obtained with a fresh printing on a one-day old coating when remeasured after
several months. Tape test densities reported herein are for fresh printings on one
month old coatings.
[0062] The scratch resistance of coated media is measured by the use of the ANSI PH1.37-1977(R1989)
method for determination of the dry scratch resistance of photographic film. The device
used is described in the ANSI IT9.14-1992 method for wet scratch resistance. Brass
weights up to 900 g. in the continuous loading mode are used to bear on a spherical
sapphire stylus of 0.38 mm radius of curvature, allowing an estimated maximum loading
of 300 kgm/cm
2. Since the stylus is a constant, the results can be reported in gram mass required
to initiate and propagate a scratch, as viewed in reflected light. Scratch data is
typically accurate to within approximately 50 gms.
[0063] Total haze of the coated media is measured with a Gardner XL-211 Hazegard System
calibrated to 1, 5, 10, 20 and 30 % haze NIST standards (standard deviation 0.02)
on 35 mm wide strips held 1.2 cm from the transmission entrance on the flat surface
of a quartz cell. The measured scattered light (TH) and the 100 % scatter transmitted
light reference (%REF) with the 100 % diffuser in place are recorded. The result is
reported as
. The internal haze is measured similarly by immersing the strip into light mineral
oil (Fisher 0121-1) in the quartz cell with the sample at the far face of the cell
(closest to the position described above). The close index of refraction match of
the mineral oil to the media allows assessment of the scattering arising from within
the coating and polyester base. The difference between these two measures of haze
is largely due to the roughness of the coated surface. The haze was observed to be
essentially independent of sample age, temperature or room humidity below 50% relative
humidity.
[0064] Tape adhesion is a quantitative measurement indicating the propensity of the phase
change ink to remain adhered to the media. The tape adhesion test is performed by
adhering a 20 cm. strip of 3M Scotch Tape type 810 Magic Tape along the upper edge
of a 3" by 8" black image printed with a Tektronix Phaser 340 in the manual transparency
mode. By grasping the unattached tape tag, the tape is pulled off of the media and
the density of the ink remaining on the tape is measured. The density on the tape
is measured in a manner analogous to the one described above for the test test density
where the density remaining on the film is measured. A tape adhesion scale is used
for comparison wherein:
a density of 0 to 0.25 is rated 4,
a density of 0.25 to 0.5 is rated 3,
a density of 0.5 to 0.75 is rated 2,
a density of 0.75 to 1.0 is rated 1,
a density of 1.0 to 1.2 is rated 0.
[0065] Impact represents a measure of the adhesion of the phase change ink under conditions
of rapid delamination with higher numbers being preferred. Impact is measured by a
Gardner Impact Tester (Cat No. 1G1121) from BYK Gardner, Silver Spring, MD. The tester
is modified by placing a rubber stopper in the drilled out anvil to a position slightly
above being flush with the top of the anvil. This is done so as to avoid gross distortions
of the PET base film upon impact by the hammer. The weight used to deliver the hammer
blow is the 85 gm weight available from BYK Gardner. A specially modified Tektronix
Phaser 340 is used to deliver in one media pass a double layer of black ink uniformly
to a 10 cm x 19 cm area and after waiting for at least five minutes for the wax layer
to come to room temperature, impacts are delivered from a height of 10 cm to each
of four spots on a line parallel so the leading edge of the printed sheet on the side
opposite the wax. One impact is delivered in the first spot, two in the second in
succession, and so on up to a maximum of four impacts in the fourth spot. After impacting,
Scotch Magic(TM) Tape (type 810) form 3M Company, St. Paul , Minnesota is applied
over the impacted spots and slowly removed to lift any dislodged ink. The sample is
then rated on a scale of 0 to 4 depending on the number of impacts required to dislodge
ink from the impacted area. The following definition of grades were used:
Grade |
Appearance |
0 |
Significant ink dislodged, in one hammer blow with complete removal with two or more
blows |
1 |
No or very little ink removed in one blow, significant ink dislodged in two blows,
and complete removal with three or more blows |
2 |
No or very little ink removed in one or two blows, significant ink dislodged in three
blows, and complete removal with four blows |
3 |
No or very little in removed with one, two or three blows, significant ink dislodged
with four blows |
4 |
No or very little ink removed using up to four consecutive blows |
[0066] The judgment of how much ink removal is considered "very little" is made by a comparison
to a region which has not been impacted but has had the tape applied and removed.
[0067] The following examples are illustrative of the invention and are not intended to
limit the invention in any manner.
EXAMPLE 1
Preparation of Coating Solutions
[0068] The polymer solution was prepared in a jacketed, stirred container at about 7-8 wt
%. The polymer, typically available as a powder, was dispersed at moderately high
shear in deionized water for a short duration. The shear was decreased, the temperature
raised to above 90°C, and the temperature maintained until the polymer was completely
dissolved (approximately 1/2 hour). The solution was cooled to 25-30°C, and the weight
percent solids determined. pH was adjusted to closely approximate that of the inorganic
particulate material. Coating aids such as Triton X-100, ethyl alcohol, antimicrobials,
Teflon beads and other additives can be added if desired. A solution containing the
inorganic particulate matter was prepared in a separate, stirred container. The polymer
solution and inorganic particulate matter solution were then combined and analyzed
to insure that pH, viscosity were suitable for coating. The mixtures were coated within
24 hours of their preparation.
[0069] Various coating solutions were prepared as detailed above with the silica types and
percentages as shown in Table 1. Conductivity (Con.) was determined in millisiemens
(mS) as described previously for the coating solution at 25°C corrected to 10%, by
weight, solids. Percent total haze (%TH) was measured by the procedure described previously
and the results were normalized to 10 mg/dm
2 coating weight. The results are recorded in Table 1.
Table 1
Sample |
Silica |
PS |
%Si |
pH |
%TH |
Con. |
|
C-1 |
CL |
0.012 |
97 |
3.7 |
103 |
1.63 |
Comp. |
C-2 |
CL |
0.012 |
96 |
3.6 |
76 |
1.61 |
Comp. |
C-3 |
SK |
0.012 |
87 |
4.3 |
95 |
0.92 |
Comp. |
C-4 |
SK |
0.012 |
82 |
4.2 |
65 |
0.87 |
Comp. |
C-5 |
SKB |
0.012 |
87 |
4.3 |
55.8 |
0.76 |
Comp. |
C-6 |
TM50 |
0.022 |
95 |
9.6 |
59 |
0.75 |
Comp. |
C-7 |
TM50 |
0.022 |
93 |
8.8 |
98 |
0.73 |
Comp. |
C-8 |
SKB |
0.012 |
82 |
4.2 |
44 |
0.72 |
Comp. |
C-9 |
LS |
0.012 |
97 |
8.6 |
10 |
0.66 |
Comp. |
C-10 |
LS |
0.012 |
96 |
8.1 |
13 |
0.65 |
Comp. |
I-1 |
TMA |
0.022 |
87 |
4.1 |
2.8 |
0.56 |
Inv. |
I-2 |
TMA |
0.022 |
82 |
3.8 |
4.0 |
0.53 |
Inv. |
I-3 |
OUP |
0.035 |
82 |
3.9 |
2.4 |
0.38 |
Inv. |
I-4 |
OUP |
0.035 |
85 |
4 |
1.9 |
0.34 |
Inv. |
I-5 |
OUP |
0.035 |
84 |
3.6 |
2.0 |
0.33 |
Inv. |
I-6 |
OUP |
0.035 |
87 |
4.2 |
1.6 |
0.29 |
Inv. |
I-7 |
OUP |
0.035 |
87 |
3.8 |
2.38 |
0.29 |
Inv. |
I-8 |
OUP |
0.035 |
87 |
4.3 |
1.23 |
0.29 |
Inv. |
I-9 |
OUP |
0.035 |
87 |
4 |
1.12 |
0.29 |
Inv. |
where:
PS is particle size in pm; %Si is the percent, by weight, of silica as a traction
of the total weight of silica and polymer; mS is the conductivity at 25°C at 10% solids,
by weight; CL is Ludox CL available from E. I. duPont de Nemours & Co. of Wilmington,
Del. USA; SK is Ludox SK available from E. I. duPont de Nemours & Co. of Wilmington,
Del. USA; SKB is Ludox SKB available from E. I. duPont de Nemours & Co. of Wilmington,
Del. USA; TM-50 is Ludox TM-50 available from E. I. duPont de Nemours & Co. of Wilmington,
Del. USA; LS is Ludox LS available from E. I. duPont de Nemours & Co. of Wilmington,
Del. USA; TMA is Ludox TMA available from E. I. duPont de Nemours & Co. of Wilmington,
Del. USA; and OUP is Snowtex-OUP available from Nissan Chemical Industry, Ltd. Tokyo,
Japan. |
[0070] The results presented in Table 1 indicate a significant reduction in total haze for
samples with a conductivity of less than 0.6 mS. Total haze is shown to be essentially
independent of particle size or pH within the ranges illustrated.
EXAMPLE 2
[0071] Samples were prepared using the coating solution of Example 1 as the only receptive
layer. The inorganic particulate material represented 88%, by weight, of the weight
of the particulate material and polymer taken together. Triton X-100 and Teflon beads
were added at levels of 5x10
-3% and 0.4%, respectively, by weight, based on the weight of the total coating solution.
Thickness was determined based on coating weight and known density of the dried coating.
Scratch resistance was determined as described previously. The results are provided
in Table 2.
Table 2
Sample |
CW |
Thick |
Scr |
|
C-11 |
33 |
1.65 |
300 |
Comp. |
C-12 |
21 |
1.05 |
250 |
Comp. |
C-13 |
16 |
0.8 |
310 |
Comp. |
I-10 |
12 |
0.6 |
425 |
Inv. |
I-11 |
10 |
0.5 |
375 |
Inv. |
I-12 |
10 |
0.5 |
320 |
Inv. |
I-13 |
8 |
0.4 |
350 |
Inv. |
I-14 |
4 |
0.2 |
500 |
Inv. |
Wherein:
CW is coating weight in mg/dm2.
Thick is thickness of the coated layer in pm calculated assuming a dried solids density
of 2.0 gm/cc.
Scr is the weight, in grams, required to initiate and propagate a scratch. |
[0072] The results of Example 2 illustrate increased scratching observed for samples with
a coating weight of greater than 15 mg/dm2.
EXAMPLE 3
[0073] Samples were prepared as described above for Example 2 using Nissan-OUP silica with
0.49%, by weight, Triton X-100 added to the coating solution. A phase change ink image
was printed on the media as described and the adhesion of the phase change ink to
the media was determined by the tape test. Tape test density was determined as described
previously. The results are provided in Table 3. Each analysis represents the average
of four independent measurements.
Table 3
Sample |
%Si |
TT |
|
I-15 |
87 |
75 |
Inv. |
I-16 |
85 |
75 |
Inv. |
I-17 |
82 |
78 |
Inv. |
C-14 |
77 |
70 |
Comp. |
Wherein %Si is the percentage of polymer and silica represented by silica; TT is tape
test density. |
[0074] The results of Example 3 illustrate that the adhesion between the inventive media
and the phase change ink is superior to the comparative examples.
EXAMPLE 4
[0075] A coating composition was prepared as described in Example 1 with 88%, by weight,
silica and 12%, by weight polyvinylalcohol for use as the lower receptive layer. A
coating weight of 5 mg/dm
2 was used for the lower receptive layer. Coating compositions for an upper receptive
layer were prepared comprising the approximate compositions in Table 4 coated at approximately
4 mg/dm
2. The soft polymer mixture comprises methyl acrylate, acrylic acid and sodium acrylate.
Table 4
Sample |
PVA |
Silica |
MA |
AA |
SA |
I-18 |
62 |
25 |
5.5 |
3.3 |
4.4 |
I-19 |
45.5 |
44.5 |
4.2 |
2.5 |
3.3 |
I-20 |
37.9 |
36.9 |
10.3 |
6.3 |
8.3 |
I-21 |
30.3 |
29.4 |
16.7 |
10.1 |
13.3 |
I-22 |
21.6 |
21.0 |
23.8 |
14.4 |
18.9 |
I-23 |
61.7 |
24.6 |
5.5 |
3.3 |
4.5 |
I-24 |
45.0 |
45.0 |
4.1 |
2.5 |
3.3 |
I-25 |
31 |
62 |
2.9 |
1.7 |
2.2 |
I-26 |
23.7 |
71.0 |
2.2 |
1.3 |
1.7 |
I-27 |
12 |
88 |
- |
- |
- |
PVA is polyvinyl alcohol with a molecular weight of ∼50,000,
MA is methyl acrylate, AA is acrylic acid, and SA is sodium acrylate. Sample I-27
is the lower receptive layer without an upper receptive layer. |
[0076] The samples were subjected to tape density test and adhesion test as describe previously.
The results are provided in Table 5.
Table 5
Sample |
TA |
AT |
I-18 |
3 |
4 |
I-19 |
3 |
4 |
I-20 |
2-3 |
4 |
I-21 |
0 |
1 |
I-22 |
0 |
1 |
I-23 |
3 |
4 |
I-24 |
3 |
2 |
I-25 |
3 |
2 |
I-26 |
0 |
1 |
I-27 |
0 |
1 |
Where TA is the tape adhesion test, AT is adhesion test in number of impacts. |
[0077] A clear improvement in the adhesion properties is illustrated in the results reported
in Table 5.
1. A process for forming a printed image comprising the steps of:
i) heating a solid phase change ink to form a pattern of phase change ink;
ii) transferring said pattern of phase change ink to a receptor where said receptor
comprises:
a 1-10 mil thick polyethylene terephthalate support; and
a 1-15 mg/dm2 receptor layer coated on said support
wherein said receptor layer comprises:
a fibrous, branched silica with an average particle size of no more than 0.3 µm; and
at least one polymer chosen from a set consisting of polyvinyl alcohol, polyacrylamide
and gelatin; and
iii) fixing said pattern of phase change ink to said receptor to form a solid image.
2. The process for forming a printed image of Claim 1 wherein said receptor layer comprises:
92-97% by weight of said silica; and
3-18% by weight of said polymer.
3. The process for forming a printed image of Claim 1 comprising no more than 10 mg/dm2 of said receptor layer coated on said support.
4. The process for forming a printed image of Claim 1 comprising the steps of:
i) heating said solid phase change ink to form said pattern of phase change ink;
ii) applying said pattern of phase change ink to a transfer surface;
iii) cooling said pattern of phase change ink on said transfer surface;
iv) transferring said pattern of phase change ink to said receptor; and
v) fixing said pattern of phase change ink to said receptor to form said solid image.
5. A process for forming a transparent recording material for phase change ink recording
comprising the steps of:
making an aqueous coating solution comprising:
water;
a binder composition comprising:
at least one polymer chosen from a group consisting of polyvinyl alcohol, polyacrylamide,
methyl cellulose, polyvinyl pyrrolidone and gelatin; and
an inorganic particulate material with an average particle size of no more than 0.3
µm wherein said inorganic particulate material represents at least 82%, by weight,
and no more than 97%, by weight, of a combined coating weight of said polymer and
said inorganic particulate material taken together;
wherein said aqueous coating solution has an ionic conductivity of no more than 0.6
mS at 25°C, at 10% total solids;
applying said coating solution to a polyethyleneterephthalate support in a sufficient
amount that said inorganic particulate material and said polymer taken together weigh
1 - 15 mg/dm2;
removing said water from said coating solution.
6. The process for forming a transparent recording material for phase change ink recording
of Claim 5 wherein said ionic conductivity of said coating solution is no more than
0.3 mS.
7. The process for forming a transparent recording material for phase change ink recording
of Claim 5 wherein said inorganic particulate material is a multispherically coupled
colloidal silica comprising at least two spheres.
8. The process for forming a transparent recording material for phase change ink recording
of Claim 7 wherein said multispherically coupled colloidal silica comprises at least
seven spheres.
9. The process for forming a transparent recording material for phase change ink recording
of Claim 5 wherein said polymer is chosen from a group consisting of polyvinyl alcohol,
polyvinyl pyrrolidone and gelatin.
10. The process for forming a transparent recording material for phase change ink recording
of Claim 5 wherein said application of said coating solution is in an amount sufficient
such that said inorganic particulate material and said polymer taken together weigh
no more than 8 mg/dm2.
11. A phase change ink recording media comprising:
a polyethylene terephthalate support;
a 1-15 mg/dm2 lower receptor layer coated on said support
wherein said lower receptor layer comprises: silica; and
at least one polymer chosen from a set consisting of polyvinyl alcohol, polyvinyl
pyrrolidone, polyacrylamide, methylcellulose and gelatin;
wherein a total weight of said polymer and said silica is 82-97%, by weight, silica
and 3-18%, by weight, polymer; and
an upper receptive layer coated on said lower receptor layer wherein said upper receptor
layer comprises:
32-70%, by weight, matrix polymer;
15-62%, by weight, inorganic particulate material; and
5-53%, by weight, soft polymer mixture.
12. The phase change ink recording media of Claim 11 wherein said upper receptor layer
comprises 40-70%, by weight, matrix polymer.
13. The phase change ink recording media of Claim 12 wherein said upper receptor layer
comprises 60-65%, by weight, matrix polymer.
14. The phase change ink recording media of Claim 11 wherein said matrix polymer comprises
at least one polymer chosen from a group consisting of polyvinyl alcohol, acrylates,
hydrolyzed polyacrylamide, methyl cellulose, polyvinyl pyrrolidone, gelatin and copolymers
thereof.
15. The phase change ink recording media of Claim 11 wherein said matrix polymer comprises
at least one copolymer of acrylic acid and vinyl pyrrolidone.
16. The phase change ink recording media of Claim 11 wherein said matrix polymer comprises
at least one polymer chosen from a group consisting of polyvinyl alcohol, polyvinyl
pyrrolidone and gelatin.
17. The phase change ink recording media of Claim 11 wherein said matrix polymer comprises
at least one polymized monomer chosen from a group consisting of vinyl alcohol, acrylamide,
and vinyl pyrrolidone.
18. The phase change ink recording media of Claim 14 wherein said matrix polymer comprises
polyvinyl alcohol.
19. The phase change ink recording media of Claim 18 wherein said matrix polymer consist
essentially of polyvinyl alcohol.
20. The phase change ink recording media of Claim 11 wherein said upper receptor layer
comprises 15-35%, by weight, inorganic particulate material.
21. The phase change ink recording media of Claim 20 wherein said upper receptor layer
comprises 20-30%, by weight, inorganic particulate material.
22. The phase change ink recording media of Claim 11 wherein said inorganic particulate
material comprises at least one compound chosen from a group consisting of silica
and alumina.
23. The phase change ink recording media of Claim 22 wherein said inorganic particulate
material is silica.
24. The phase change ink recording media of Claim 23 wherein said silica has a particle
size of no more than 0.3 µm.
25. The phase change ink recording media of Claim 23 wherein said silica comprises at
least two particles coupled together.
26. The phase change ink recording media of Claim 25 wherein said silica comprises at
least five particles coupled together.
27. The phase change ink recording media of Claim 11 wherein said upper receptor layer
comprises 10-50%; by weight, soft polymer mixture.
28. The phase change ink recording media of Claim 11 wherein said soft polymer mixture
comprises methyl acrylate.
29. The phase change ink recording media of Claim 28 wherein said soft polymer mixture
comprises 2-24%, by weight, methyl acrylate.
30. The phase change ink recording media of Claim 29 wherein said soft polymer mixture
comprises 5-6%, by weight, methyl acrylate.
31. The phase change ink recording media of Claim 11 wherein said soft polymer mixture
comprises acrylic acid.
32. The phase change ink recording media of Claim 31 wherein said soft polymer mixture
comprises 1-10%, by weight, acrylic acid.
33. The phase change ink recording media of Claim 32 wherein said soft polymer mixture
comprises 3-4%, by weight, acrylic acid.
34. The phase change ink recording media of Claim 11 wherein said soft polymer mixture
comprises sodium acrylate.
35. The phase change ink recording media of Claim 34 wherein said soft polymer mixture
comprises 1-19%, by weight, sodium acrylate.
36. The phase change ink recording media of Claim 35 wherein said soft polymer mixture
comprises 4-5%, by weight, sodium acrylate.
37. The phase change ink recording media of Claim 11 wherein said soft polymer mixture
comprises 2-6%, by weight, methyl acrylate, 1-4%, by weight, acrylic acid, and 2-5%,
by weight, sodium acrylate.
38. The phase change ink recording media of Claim 37 wherein said soft polymer mixture
comprises 5-6%, by weight, methyl acrylate, 3-4%, by weight, acrylic acid, and 4-5%,
by weight, sodium acrylate.
39. The phase change ink recording media of Claim 11 wherein said lower receptor layer
comprises:
89-95%, by weight, said silica; and
5-11%, by weight, of said polymer.
40. The phase change ink recording media of Claim 39 wherein said lower receptor layer
comprises:
90-95%, by weight, said silica; and
5-10%, by weight, said polymer.
41. The phase change ink recording media of Claim 11 wherein said particle size of said
silica is no more than 0.3 µm.
42. The phase change ink recording media of Claim 11 wherein said silica comprises at
least two particles coupled together.
43. The phase change ink recording media of Claim 42 wherein said silica comprises at
least five particles coupled together.
44. The phase change ink recording media of Claim 11 wherein said polymer is chosen from
a group consisting of polyvinyl alcohol, polyacrylamide and methylcellulose.
45. The phase change ink recording media of Claim 46 wherein said polymer is polyvinyl
alcohol.
46. The phase change ink recording media of Claim 11 wherein said upper receptor layer
further comprises large particles.
47. The phase change ink recording media of Claim 46 wherein said large particles are
over 6 µm in size.
48. The phase change ink recording media of Claim 46 comprising 10-80 of said large particles
per 5000 µm2 of media.
49. The phase change ink recording media of Claim 48 comprising 40-60 of said large particles
per 5000 µm2 of media.